sphinx （coreseek）——2、区段查询实例

[b]首先需要知道区段查询的定义：[/b]

索引系统需要通过主查询来获取全部的文档信息，一种简单的实现是将整个表的数据读入内存，但是这可能导致整个表被锁定并使得其他操作被阻止（例如：在MyISAM格式上的INSERT操作），同时，将浪费大量内存用于存储查询结果，诸如此类的问题吧。 为了避免出现这种情况，CoreSeek/Sphinx支持一种被称为 区段查询的技术. 首先，CoreSeek/Sphinx从数据库中取出文档ID的最小值和最大值，将由最大值和最小值定义自然数区间分成若干份，一次获取数据，建立索引。现举例如下：

例 3.1. 范围查询用法举例

# in sphinx.conf

sql_query_range    = SELECT MIN(id),MAX(id) FROM documents
sql_range_step = 1000
sql_query = SELECT * FROM documents WHERE id>=$start AND id<=$end

如果这个表（documents）中，字段ID的最小值和最大值分别是1 和2345，则sql_query将执行3次：

将

$start

替换为1，并且将

$end

替换为 1000;

将

$start

替换为1001，并且将

$end

替换为 2000;

将

$start

替换为2001，并且将

$end

替换为 2345.

显然，这对于只有2000行的表，分区查询与整个读入没有太大区别，但是当表的规模扩大到千万级（特别是对于MyISAM格式的表），分区区段查询将提供一些帮助。

以上是coreseek 文档上的定义，分享一下本机测试实例：

之前做一套域名MX解析系统的时候获取过几百万的域名www title 信息，下面就用检索www 网站titile 数据来测试。

编辑用于测试的 coreseek 配置文件 csft.range.conf

source src
{
type                    = mysql
# some straightforward parameters for SQL source types
sql_host                = localhost
sql_user                = root
sql_pass                = xxxxxxxxxxxxx
sql_db                  = whomx
sql_port                = 3306  # optional, default is 3306
sql_query_pre           = SET NAMES utf8
sql_query_pre           = SET SESSION query_cache_type=OFF
　　　　 sql_query               = \
SELECT i.id,title \
FROM  mx_domain_wwwinfo i \
WHERE id>=$start AND id<=$end
sql_query_range        = SELECT MIN(id),MAX(id) FROM mx_domain_wwwinfo
}

index 配置只需要配置中文字符编码 还有中文词库的位置就可

indexer searchd 不需要更改。

接下来测试一下，

生成索引：

root@timeless-HP-Pavilion-g4-Notebook-PC:/usr/local/coreseek/etc# /usr/local/coreseek/bin/indexer -c /usr/local/coreseek/etc/csft.range.conf   --all --rotate
Coreseek Fulltext 4.1 [ Sphinx 2.0.2-dev (r2922)]
Copyright (c) 2007-2011,
Beijing Choice Software Technologies Inc (http://www.coreseek.com)

using config file '/usr/local/coreseek/etc/csft.range.conf'...
WARNING: failed to open pid_file '/usr/local/coreseek/var/log/searchd.pid'.
indexing index 'src'...
WARNING: Attribute count is 0: switching to none docinfo
collected 1500837 docs, 92.2 MB
sorted 17.5 Mhits, 100.0% done
total 1500837 docs, 92186221 bytes
total 34.680 sec, 2658122 bytes/sec, 43275.54 docs/sec
total 16 reads, 0.023 sec, 3631.5 kb/call avg, 1.4 msec/call avg
total 143 writes, 0.105 sec, 912.1 kb/call avg, 0.7 msec/call avg

根据某个关键词测试：

root@timeless-HP-Pavilion-g4-Notebook-PC:/usr/local/coreseek/bin# ./search -c /usr/local/coreseek/etc/csft.range.conf  济南
Coreseek Fulltext 4.1 [ Sphinx 2.0.2-dev (r2922)]
Copyright (c) 2007-2011,
Beijing Choice Software Technologies Inc (http://www.coreseek.com)

using config file '/usr/local/coreseek/etc/csft.range.conf'...
index 'src': query '济南 ': returned 1000 matches of 11040 total in 0.005 sec

displaying matches:
1. document=53592, weight=1664
id=53592
domain_id=75937
title=?????????????,??????,??????,?????????????????????????????????????,??????,??????,????,????,??????,??????,??????,??????,????????,????,??????,??????,??????,??????,????????,????????,?????????,?????????
addtime=1419001556
2. document=156494, weight=1663
id=156494
domain_id=320070
title=??--??????,?????,????????,????????,??????,??????,?????,?????,???,?????,?????,?????,?????,????,????,??????,??????,??????,?????,?????,?????,???,???????,
addtime=1419041933
3. document=53624, weight=1661
id=53624
domain_id=74960
title=???????-???.??.???.???????/?????/?????/?????????/?????/?????/???? ????? ????? ????? ????? ????? ????? ??POS??? ????? ????? ????? ??POS?
addtime=1419001559
4. document=908267, weight=1661
id=908267
domain_id=3482035
title=???????-???.??.???.???????/?????/?????/?????????/?????/?????/???? ????? ????? ????? ????? ????? ????? ??POS??? ????? ????? ????? ??POS?
addtime=1421983846
5. document=1074259, weight=1659
id=1074259
domain_id=2805964
title=?????? - ???? | ????? | ????? | ?????? | ?????? | ?????? | ?????? | ?????? | ?????? | ?????? | ?????? | ?????? | ?????? | ??????
addtime=1421998317
6. document=628662, weight=1658
id=628662
domain_id=1603934
title=????????|????????|?????????|?????????|??????|?????|????????????????|????????|?????????|?????????|??????|?????|????????
addtime=1420628500
7. document=82498, weight=1656
id=82498
domain_id=75205
title=???????????????????????????????????????????????????????????????????????????????????????????????????????
addtime=1419030813
8. document=373234, weight=1656
id=373234
domain_id=75953
title=????|??????|????????|??????|??????|??????|??????|??????|??????|??????|??????-????????
addtime=1419481313
9. document=97657, weight=1655
id=97657
domain_id=75152
title=????????????????????????????????????????????????????????????????????
addtime=1419032238
10. document=108426, weight=1655
id=108426
domain_id=76651
title=??????|??????|??SKF??|??NSK??|??FAG??|??NTN??|??KOYO??|??TIMKEN??|??FAG??|????|????????|????????|??????|-??
addtime=1419033228
11. document=184337, weight=1655
id=184337
domain_id=75654
title=???????|??????????|???????|??????????|??????|???????|?????????|????????|?????????|???????|??????????
addtime=1419043496
12. document=246303, weight=1655
id=246303
domain_id=262037
title=???? ?????? ?????? ?????? ????? ?????? ???? ???? ?????? ???? ??????
addtime=1419046975
13. document=261372, weight=1655
id=261372
domain_id=544595
title=??????|????|?????|?????????|???????????|??????|??????|????|?????|?????|?????|?????
addtime=1419215630
14. document=1163692, weight=1655
id=1163692
domain_id=2514244
title=??????????????????????????????????????????????????????????????????????????????_??????????????
addtime=1422005290
15. document=1163740, weight=1655
id=1163740
domain_id=2514240
title=?????????????????????????????????????????????????????????????????????????_??????????????
addtime=1422005293
16. document=1163762, weight=1655
id=1163762
domain_id=2514239
title=????????????????????????????????????????????????????????????????????????????_??????????????
addtime=1422005295
17. document=10694, weight=1653
id=10694
domain_id=454049
title=??????|??????|??????|??????|??????|?????|??????|????????|???????????|????????????|???400-070-3005
addtime=1418996572
18. document=15876, weight=1653
id=15876
domain_id=66098
title=????????? ???????????? ??????? ?????????? ??????? ??????? ????????? ??????? ??????? ???????_?????????
addtime=1418997101
19. document=23385, weight=1653
id=23385
domain_id=421622
title=????0531-82825553|??????|??????????????|????????|???????|??????|????T1|????T3|????T6|????U8
addtime=1418997836
20. document=34628, weight=1653
id=34628
domain_id=320077
title=????|?????|?????|?????|?????|?????|?????|?????|????|??????????
addtime=1418998927

words:
1. '济南': 11040 documents, 22214 hits

可以看到结果 ：1. '济南': 11040 documents, 22214 hits 以上显示只是 编码问题。

　　 接下来还有个问题 比如 现在 要增量索引跟区段查询综合在一起怎么办？ 下面文章根据百度文库里找到的一篇关于

《千万级Discuz!数据全文检索方案（Sphinx）》 综合使用coreseek 实现检索。